Negative pressure dispense system comprising a dispense assembly and mateable coupling head

ABSTRACT

A negative pressure dispense system comprises a dispense assembly to be fitted to a drum or other fluid container, and a coupling head to mate with the dispense assembly. The dispense assembly has an air valve to control the ingress of air to the fluid container and a fluid valve to control the egress of fluid from the fluid container. The coupling head seals solely with and opens the fluid valve. The dispense assembly and coupling head have complementary mating features that inter-engage upon relative mating movement between the dispense assembly and the coupling head. The dispense assembly fluid valve has a rotatable valve member, the coupling head has a part shaped to engage the rotatable valve member, and the dispense assembly and coupling head mating features inter-engage upon relative rotation whereby, in use, as the coupling head is rotated in the dispense assembly the mating features engage and the coupling head part engages and rotates the rotatable valve member to open the fluid valve.

This invention relates to fluid couplings for negative pressure dispensesystems and it particularly, but not exclusively, relates to fluidcouplings that are suitable for use with drums for hazardous chemicalsand the like.

There is a class of fluid dispense systems employing negative pressuredispensation of fluids from containers, such as expensive or hazardousliquid chemicals, the container being fitted with a dispense valveassembly that is to be mated with a coupling head at a point of use toenable the fluid to be pumped from the container. An example of acoupling for such a negative pressure dispense system is described inEuropean Patent Specification No. EP-A-0 477 477 wherein the maleassembly or coupling is fitted to the valve assembly by means of anattachment collar 27 slidingly received about the body 200 of thecoupling 51 and having four attachment lugs 274; in use, the coupling isfirst fitted into the dispense valve, opening all the valves and onlythereafter is the collar rotated to lock the valve in position. Such anarrangement is clearly dangerous in that hazardous chemicals couldescape from an unsecured coupling.

It is an object of the present invention to provide a fluid coupling fornegative pressure dispensing of fluids wherein the fluid valve cannot beopened without mating engagement between the coupling head and thedispense assembly.

According to the present invention, a fluid coupling for a negativepressure dispense system comprises a dispense assembly to be fitted to adrum or other fluid container, and a coupling head to mate with thedispense assembly, the dispense assembly having an air valve to controlthe ingress of air to the fluid container and a fluid valve to controlthe egress of fluid from the fluid container, the coupling head sealingsolely with and opening the fluid valve, and the dispense assembly andcoupling head having complimentary mating features that inter-engageupon relative, mating movement between the dispense assembly and thecoupling head, wherein the dispense assembly fluid valve has a rotatablevalve member, the coupling head has a part shaped to engage therotatable valve member, and the dispense assembly and coupling headmating features inter-engage upon relative rotation, whereby, in use, asthe coupling head is rotated in the dispense assembly the matingfeatures engage and the coupling head part engages and rotates the valvemember to open the fluid valve.

In an embodiment of the present invention, the rotatable valve member isof an inverted cup shape having radial ports in the cup side walls andis rotatable about a vertical axis on a valve support member that ispart of the dispense assembly and is provided with radial ports thatcommunicate with a through bore in the valve support member; whereby, inuse, the valve member can be rotated so that its ports register with thesupport member ports to open the fluid valve.

Preferably, the rotatable valve member has a cruciform depression in itsupper surface and the coupling head terminates in a central cruciformextension comprising said part shaped to engage the rotatable valvemember. The coupling head may have a through bore housing a one-wayfluid valve and the cruciform extension may have surrounding axial portscommunicating with the one-way valve.

The above and other features of the present invention are illustrated,by way of example in the Drawings, wherein:

FIG. 1 is a sectional elevation of an unmated coupling head and dispensecap in accordance with a first embodiment of the present invention; and,

FIG. 2 is a similar view of the coupling head and dispense cap of FIG.1, when mated.

The fluid coupling shown by FIGS. 1 and 2 generally comprises a dispensecap 70 and a coupling head 112. The dispense cap is a plastics mouldingof generally conventional cap shape, or it could be an adapted cap, witha depending threaded skirt 74, a top 76 and a cap seal 78 to sealagainst the lip of the neck of a container or drum (not shown), forexample a type 2001 plastic drum). A frusto-conically shaped socket 80is co-axially, sealingly fitted into the cap top. The top of the socketis provided with a radially outwardly extending flange 82 that isattached to the cap top. The socket also has a central recess 84 and abore 86 running from the bottom of the recess to the inner end 88 of thesocket body. The lower part of bore 86 is of larger diameter than theupper part and a plastics tube 90 is fitted within the lower bore anddepends to the bottom of the drum. The socket duct is sealed by a fluidvalve 92 having a rotary valve member 94. The valve member is of aninverted cup shape having radial ports 96 (FIG. 2) in the cup side walls98 and can rotate about a vertical axis on a valve support member 100,part of the socket body 80, that is provided with radial ports 102(FIG. 1) that communicate with the through bore 86. Valve member 94 canbe rotated so that its ports 96 can register with the support member'sports 102, i.e. the fluid valve will be open (FIG. 2). The valve isclosed when the valve seal is rotated away from port registration (FIG.1). Valve member 98 also has a cruciform depression 104 in its uppersurface.

A ring of air holes 106 in the bottom of the recess 84 surround the bore86, running axially from the recess to emerge under the socket flange82. A resilient, annular air valve diaphragm 108 is seated in aperipheral groove 110 about the exterior of the socket body and isbiassed against the underside of the socket flange to thereby normallyseal the air holes 106. The socket recess 84 is also provided with apair of circumferentially short, radially inwardly extending flanges109.

The coupling head 112 generally comprises a radially winged,cylindrically shaped moulding of plastics material the front end 114 ofwhich is provided with circumferentially short, radially outwardlyextending flanges 116 that are designed to inter engage in a bayonettype fitting with the inwardly extending flanges 109 in the dispense capcentral recess 84. The coupling head has a through bore 118 thatterminates in a larger diameter bore. A spring-loaded, non-return ballvalve 120 is housed in the larger diameter bore. The coupling headterminates in a central cruciform extension 122; with surrounding axialports 124 communicating with non-return ball valve 120. A sealing ring126 is provided at the coupling head front end radially outside theaxial ports 124. The upper end of the coupling head is threaded at 128for connection to an outlet pipe, not shown.

In use, the coupling head 112 is mated to the dispense cap 70 byintroducing the coupling head 114 front end into the cap socket recess84 and rotating the coupling head a part-turn relative to the dispensecap so that the coupling head bayonet flanges 116 engage under thedispense cap socket bayonet flanges 109. As the coupling head enters thedispense cap socket, the coupling head cruciform extension 122 entersfluid valve member cruciform depression 104 and, as the coupling head112 is rotated, valve member 94 is rotated from its closed to its openedposition. Sealing ring 126 is compressed against the bottom of thesocket recess 84 to seal the coupling head front end in the dispense capsocket. A suction pump (not shown) is connected to the coupling headupper end 128 so that L can be pumped out of the drum; passing up tube90, through the fluid valve ports 102 & 96, through axial ports 124 upinto the coupling head front end 114, past the ball valve 120 to theoutlet from the coupling head (as indicated by the arrows in FIG. 2). Aspressure in the drum drops air will pass the coupling head front end114, between the coupling head flanges 116, to flow through the airholes 106 into the head space in the drum; the differential air pressurelifting air valve diaphragm 108 off the underside of the socket flange(again as indicated by the arrows in FIG. 2). The cap skirt 74 may beprovided with an anti-tamper ring 130 of known type and the cap socketrecess 84 may be provided with a transit bung (not shown).

I claim:
 1. A negative pressure dispense system comprising a dispenseassembly to be fitted to a fluid container, and a coupling head to matewith the dispense assembly, the dispense assembly having an air valve tocontrol the ingress of air to the fluid container and a fluid valve tocontrol the egress of fluid from the fluid container; the coupling headsealing solely with and opening the fluid valve; and the dispenseassembly and coupling head having complimentary mating features thatinter-engage upon relative, mating movement between the dispenseassembly and the coupling head, wherein the dispense assembly fluidvalve has a rotatable valve member, the coupling head has a part shapedto engage the rotatable valve member, and the dispense assembly andcoupling head mating features inter-engage upon relative rotation;whereby, in use, as the coupling head is rotated in the dispenseassembly the mating features engage and the coupling head part engagesand rotates the rotatable valve member to open the fluid valve.
 2. Asystem as claimed in claim 1 wherein the rotatable valve member is of aninverted cup shape having radial ports in the cup side walls and isrotatable about a vertical axis on a valve support member that is partof the dispense assembly and is provided with radial ports thatcommunicate with a through bore in the valve support member; whereby, inuse, the valve member can be rotated so that its ports register with thesupport member ports to open the fluid valve.
 3. A system as claimed inclaim 2 wherein the rotatable valve member has a cruciform depression inits upper surface and the coupling head terminates in a centralcruciform extension comprising said part shaped to engage the rotatablevalve member.
 4. A system as claimed in claim 3 wherein the couplinghead has a through bore housing a one-way fluid valve and the cruciformextension has surrounding axial ports communicating with the one-wayvalve.
 5. A system as claimed in claim 2 wherein the dispense assemblyand the coupling head have part-turn, inter-engaging fittings.
 6. Asystem as claimed in claim 5 wherein the part-turn, inter-engagingfittings are bayonet fittings.
 7. A system as claimed in claim 1 whereinthe air ingress valve is a one-way valve provided in the dispenseassembly co-axially with the fluid valve.
 8. A system as claimed inclaim 7 wherein the one-way valve is an annular air valve diaphragmdisposed about the fluid valve and biased to seal air inlet ports in thedispense assembly.